Dead end clamp for cables



Nov. 21, 1933. E. NOYES 1.936,097

DEAD END CLAMP FOR CABLES Filed April 19, 1930 4 Sheets-Sheet 1 FIG. I.

Nov. 21, 1933. M. E. NOYES 1,936,097

DEAD END CLAMP FOR CABLES Filed April 19, 1930 4 Sheets-Sheet 2 ll lm" I s E k FIG. 2.

Nov. 21, 1933.

A M. E. NOYES 1,936,097

DEAD END CLAMP FOR CABLES Filed April 19, 1930 4 Sheets-Sheet 3 FIG. 4.

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(I5 9 LL 2 L8 LL w M gm%emboz w d 51 13 at/towel 7J4 Nov. 21, 1933. M. E. NOYES DEAD END CLAMP FOR CABLES Filed April 19, 1930 4 SheetsSheet 4 Svwemtoz $1 fitter/n 4 Patented Nov. 21, 1933 UNITED STATES DEAD CLAMP FOR CABLES Maxwell E. Noyes, Mount Lebanon, Pa., ass'ignor to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania v Application April 19, 1930. "Serial N6. 445,581 6 Claims. (01. 24 -135) V This invention relates to strain clamps for steel reinforced aluminum cables and more particularly relates to improvements in the details of construe tion of such; devices to the general end that simplicity may be obtained with attendant low cost. 1 l

A'furth er object of the present invention resides in the provision of a strainvclamp provided with an accelerating curved and grooved notch for re- ,10 ceiving and snubbing the cable, which accelerating curve is co-planar with the reach of the cable whereby compactness and simplicity of construction may be obtained while still maintaining desired snubbing action upon the cable.

A further object of the present invention ree sides in the provision of a strain clamp having grooved portions provided with an accelerating curve forreceiving and snubbing the cable and which clfamp also has a gripping means disposed beyondthe accelerating curved notch and. disposed in alignment therewith whereby secure snubbing and clamping may be obtained by the device and with a compact disposition of the parts.

Further and other objects of the present invention will be hereinafter set forth in the accompanying specification and claims and shown in the draWingS; which by way of illustration show what I now consider to be a preferred em- 3 bodiment of the invention.

In the drawings:

Figure 1 shows a' pair of strain clamps associated with supportingiinsulatorsy Fig. 2 is an enlarged side view shown partly in section of one of the improved strain clamps;

Fig. 3 shows a detail sectional View of the clamping or cable securing means; this section istaken on line 3-3 of Fig. 2; j

5 Fig. 4 is a top plan view of the part shown in Fig. 2, the view being taken along the line 4-4 of Fig. 2 and looking in the direction of the arrows;

Fig. 5 is an end view taken from the right on Fig. 2 substantially along line 55 and looking in the direction of the arrows;

Fig. 6 is a side view ofthe gripping device, the view being taken substantially along line 66 and looking in the direction of the arrows;

Figs. 7, 8 and 9 are sections through the notched portion of the clamp, the sections being taken substantially on lines 77, 8+8 and 9-'-9 of Fig. 2; J

Fig. 10 is a view similar to Fig. 2 of a modified form of clamp in which a diiferent form of gripping element is provided;

Fig. 1 1 is a detail sectional view taken on' line 11--l 1 of Fig. l0; and

Fig. 12 is a'view of certain parts shown'in Fig. 10, WhlCh'ShOWS the relation of the gripping elements withrespect to the U bolt before assembly 0 M is complete.

In'more detail referringtoFig. 1. 10 represent supporting Qinsulators. The strain relieving cable securing devices generally designated 11,. are suitably pivotally connected to the insulators by pivotbolts 12"and each strain relieving device comprises a light weight casting having a pair of-spacedarn portions 13 (see Fig. 4). and an intermediate notched cable receiving. portion 14. This notched portion 14 is disposed 00- planar with the reach'of the cable'1'5 and the notch is symmetrical with respect to a median plane '16 (Fig. 4). The shape of the cross section of the curved notch at various points is shown in Figs. '7. 8 and 9. As best shown in Fig. 2 the cable receiving notched portion 14 is shaped with an accelerating curve 17. This curve. is not a true circle but is of largeradius where the cable enters the clamp where the tension is .maximum and thereafter gradually decreases in radius, thus efiecting an increased snubbing action as the tension in the cable falls off. Thus thenotchedcable receiving portion or groove 14 extends rearwardly from the point of entry of the taut portion or reach of the cable toward the point of attachment of the strain f clamp "at 12, and forwardly away from the point of attachment toward the point of cooperation of the cable withthe clamping member 19 in the portion 18 of the groove-and toward the point of exit adjacent the slackportion of the cable. The curvature of the groove is greatest at points remote from the point of entrance of the taut portion or reach of the cable into the. groove 14. From the intermediate point (near the section line 9-9, Figl 2), in the strain clamp which is closest to the point of attachment at 12, the groove 14 extendsforwardly to the point of entrance of the reach of the cable and forwardly to the point of cooperation with the clamping member 19. The curvature. of the groove decreases from the intermediate point towards the point of entrance of the reach of the cable and the curvature of thegroove increases from the intermediate point toward the clamping point and toward the point of exit of the slack portion of the cable. By providing the notched or grooved portion with the acceleratingv curve and disposing it co-planar with the reach ofthecable and locating the curved notch being wholly co-planar with the reach of the.

cable) is that turning moment does not occur at the point of attachment when strain is applied to the cable.

Cable gripping and clamping devices At the end of the accelerating curve 17 and groove 14, where the radius of the curve 1'? is the least, the cable receiving member is extend-- ed and provided with a reverse curved notched portion, generally designated 18 in Fig. 2. The groove of this reversely curved notched portion is substantially in alignment with the groove 14. The cable is gripped with respect to the reverse curved and grooved portion 18 by means of a gripping or clamping element 19 which has proper curvature to secure the desired gripping action of the cable upon the reverse curved notched portion of the cable receiving member. The gripping element 19 is provided with an aperture 20 therethrough adapted to receive a U bolt 21. This U- bolt in turn passes through openings in extended portions of the casting to the sides of the reverse curved notched portion 18 and is suitably secured by means such as nuts 22 (see Fig. 3). v

According to the modification shown in Fig. 10', two reverse curved gripping notches 18a and 181) are provided in lieu of one and the gripping elements 19a and 1917 are arranged to clamp the cable tightly against these reverse curved notched portions. In lieu of providing an aperture through members 19a and 19b to receive the fastening U bolts 21, the elements 190:. and 1% are initially formed with open tongue or clamp portions 23 (see Fig. 12) which are afterwards peened over as indicated at 2317 (see Fig. 10').

' I claim:

I. A strain clamp for a cable comprising a strain relieving member provided with a grooved portion which is shaped with an accelerating curve, said groove from end to end being entirely co-planar with the reach of the cable which is received in and snubbed by the accelerating curved groove of the strain relieving member and a clamping member directly clamping the'cable in the groove of the strain relieving member in a direction normal to the bottom of the groove, the aforesaid accelerating curved portion of the groove having one portion extending rearwardly from the'point of entry of the reach of the cable toward the point of attachment of the strain clamp and another portion extending forwardly away from the said point of attachment toward the point of cooperation of the cable with the clamping member and the point of exit of the cable.

2. A strain clamp for a cable comprising a strain relieving member provided with a grooved cable receiving portion shaped with an accelerating curvature which is. greatest at points remote from the point of entrance of the reach of the cable into the groove to provide progressively in creasing snubbing action, said groove being from end to end entirely co-planar with the reach of the cable whereby twisting strains upon the strain relieving member are minimized and whereby turning moment does not occur at the point of attachment of the strain relieving member when strain is applied to the cable, and a clamping member clamping the cable directly against the bottom of the groove and in a direction normal thereto, said clamping member and the groove adjacent thereto providing for reversed curvature of the cable and increased snubbing action of the cable in the groove adjacent the clamp with the cable free in the groove throughout the length of the latterup to said clamping member, saidstrain relieving member having its accelerating curved groove shaped and disposed so that the cable extends forwardly from an intermediate point adjacent the point of attachment of the strain relieving member to the point of entrance of the reach of the cable and so that the cable also extends forwardly from the said intermediate point to the point of cooperation with the clamp. I I

3. A clamping and strain relieving device for a cable, said device comprising a member with a snubbing. groove for receiving a cable, and

clamping means cooperating with the cable for clamping the cable toward the bottom of the snubbing groove, said snubbing groove leading the cable from its reach successively toward and then away from the point of attachmentof the device, said snubbing groove throughout its length being entirely co-planar with the reach of the cable and with progressively diminishing curvature from the point of maximum snubbi'ng adjacent the clamp to the point of entrance of the reach of the cable, said clamping means cooperating with the cable in such groove in such direction that the effect of clamping and the stress of the taut reach of the cable both cooperate to force the cable to the bottomof the groove to provide progressively increased snubbing action of the cable in the groove while minimizing twisting strains upon the member and obviating torsional strains at the point of attachment of the device and strains upon the cable transversely of the groove.

4. A strain clamp for a cable including a strain. relieving device having a clamping, portion and constructed for progressively increased direct snubbing action both against the cable and only in the plane of the reach of the cable, from its point of entry to and through the clamping portion, said device including a snubbing groove entirely co-planar with the reach of the. cable and extending from the point of entry of the cable rearwardly toward the point of attachment of the device and then forwardly away from said point portion of said device including a clamping member constructed for clamping action against the cable in a direction normal to the bottom of the groove and with the cable co-planar with its reach. 7

5. A strain clamp for a cable comprising a strain relieving member in which is formed a groove of increasing curvature, said groove extending rearwardly from the point of entry of the taut portion of the cable toward the point of attachment of said strain clamp and forwardly away from said point of attachment toward the point of exit adjacent the slack portion of the cable, said groove being wholly co-planar with the reach of the cable which extends thereinto so that turning moment does not occur at the forwardly toward the point of exit adjacent the slack portion of the cable with increasing curvature away from said point of attachment of the strain clamp, said groove being disposed entirely symmetrically with respect to a median plane which intersects the center of the groove so that turning moment does not occur at the point of attachment when strain is applied to the cable.

' MAXWELL E. NOYES. 

